The suprachiasmatic nucleus in the hypothalamus is the master circadian clock in mammals,coordinating physiological processes with the 24-hour day–night cycle.Comprising various cell types,the suprachiasmatic nucleus...The suprachiasmatic nucleus in the hypothalamus is the master circadian clock in mammals,coordinating physiological processes with the 24-hour day–night cycle.Comprising various cell types,the suprachiasmatic nucleus(SCN)integrates environmental signals to maintain complex and robust circadian rhythms.Understanding the complexity and synchrony within SCN neurons is essential for effective circadian clock function.Synchrony involves coordinated neuronal firing for robust rhythms,while complexity reflects diverse activity patterns and interactions,indicating adaptability.Interestingly,the SCN retains circadian rhythms in vitro,demonstrating intrinsic rhythmicity.This study introduces the multiscale structural complexity method to analyze changes in SCN neuronal activity and complexity at macro and micro levels,based on Bagrov et al.’s approach.By examining structural complexity and local complexities across scales,we aim to understand how tetrodotoxin,a neurotoxin that inhibits action potentials,affects SCN neurons.Our method captures critical scales in neuronal interactions that traditional methods may overlook.Validation with the Goodwin model confirms the reliability of our observations.By integrating experimental data with theoretical models,this study provides new insights into the effects of tetrodotoxin(TTX)on neuronal complexities,contributing to the understanding of circadian rhythms.展开更多
Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in ge...Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in general net theory(GNT), a quantitative method for structure description and analysis of information systems was introduced. Results The structural complexity index and two related factors, i.e. element complexity factor and connection complexity factor were defined, and the relations between them and the parameters of the Petri net based model of the system were derived. Application example was presented. Conclusion The proposed method provides a theoretical basis for quantitative analysis and evaluation of the structural complexity and can be applied in the general planning and design processes of the information systems.展开更多
The horizontal distribution of stems, stand density and the differentiation of tree dimensions are among the most important aspects of stand structure. An increasing complexity of stand structure is often linked to a ...The horizontal distribution of stems, stand density and the differentiation of tree dimensions are among the most important aspects of stand structure. An increasing complexity of stand structure is often linked to a higher number of species and to greater ecological stability. For quantification, the Structural Complexity Index (SCI) describes structural complexity by means of an area ratio of the surface that is generated by connecting the tree tops of neighbouring trees to form triangles to the surface that is covered by all triangles if projected on a flat plane. Here, we propose two ecologically relevant modifications of the SCI: The degree of mingling of tree attributes, quantified by a vector ruggedness measure, and a stem density term. We investigate how these two modifications influence index values. Data come from forest inventory field plots sampled along a disturbance gradient from heavily disturbed shrub land, through secondary regrowth to mature montane rainforest stands in Mengsong, Xishuangbanna,Yunnan,China. An application is described linking structural complexity, as described by the SCI and its modified versions, to changes in species composition of insect communities. The results of this study show that the Enhanced Structural Complexity Index (ESCI) can serve as a valuable tool for forest managers and ecologists for describing the structural complexity of forest stands and is particularly valuable for natural forests with a high degree of structural complexity.展开更多
Beethoven is a famous German pianist, composer, and conductor, and he set the culmination of Western classical, created a romantic music camp precedent. The size of his music in general is very ambitious, mostly conce...Beethoven is a famous German pianist, composer, and conductor, and he set the culmination of Western classical, created a romantic music camp precedent. The size of his music in general is very ambitious, mostly concertos, symphonies, operas and other large works, technical approach and structure used is quite complex, people are left with a deep impression. But it works, while small piano pieces, also has music research value, ＂dedicated to Alice＂ is one of the few Beethoven piano pieces. This paper focuses on creative background ＂dedicated to Alice,＂ this elaborate piano works by the complexity of the analysis of the structure of this work is that it reflects the author＇ s ideological soul to explore their musical value.展开更多
Structural complexity is a critical factor in maintaining the key ecosystem services of coral reefs,such as fisheries,biodiversity,coastal protection,and ecotourism.However,the resilience of coral reefs to climate cha...Structural complexity is a critical factor in maintaining the key ecosystem services of coral reefs,such as fisheries,biodiversity,coastal protection,and ecotourism.However,the resilience of coral reefs to climate change and anthropogenic disturbances remains poorly understood owing to a lack of longterm data.This study used data from field surveys at Weizhou Island in the northern South China Sea,conducted from 2019 to 2024,to record the response trajectories of the coral community and structural complexity,and to estimate the key drivers in a relatively high-latitude coral reef.Following a bleaching event in 2020 and disturbance by two cyclones in 2023,live coral cover(LCC) initially declined but later recovered,suggesting a gain in thermal tolerance.Corals in the marine protected area(MPA) were less impacted than those in the non-protected area.However,the structural complexity decreased continuously,from 1.200 to 1.076,signifying simplification in coral morphological composition.Despite the decline in structural complexity,a significant positive correlation with fish density was observed in the MPA(R^(2)=0.91,p<0.05).Bayesian and generalized linear models identified thermal stress,cyclones,and anthropogenic activity as the primary drivers of the loss of structural complexity.These results,along with the divergent trajectories of LCC and structural complexity,highlight the limited resilience of a relatively high-latitude coral reef to climate change.The findings of this study demonstrate how an MPA can play a crucial role in enhancing ecosystem resilience by reducing local stressors and allowing marine life to recover,enabling the ecosystem to withstand a wider-reaching threat such as climate change.We recommend incorporating structural complexity into long-term monitoring and management networks for coral reef ecosystems facing climate change.展开更多
Text,as a fundamental carrier of human language and culture,exhibits high structural and semantic complexity.Its systematic analysis is essential for understanding linguistic patterns and cultural transmission.A Dream...Text,as a fundamental carrier of human language and culture,exhibits high structural and semantic complexity.Its systematic analysis is essential for understanding linguistic patterns and cultural transmission.A Dream of Red Mansions and All Men Are Brothers,two masterpieces of Chinese classical literature,have long been central to debates regarding the authorship of their later chapters.Previous studies,often based on word-frequency statistics,function word distributions,entropy measures,and complex network analyses,have provided valuable insights into stylistic differences;however,they remain limited in capturing cross-scale structural features.To address this gap,we apply a multi-scale structural complexity approach based on character-frequency time series to analyze the structural evolution of both novels under various segmentation strategies.Our results reveal significant differences in peak complexity positions,overall complexity levels,and intra-textual variations between the two works,which are closely linked to changes in authorship and stylistic patterns.This study not only provides new quantitative evidence for resolving authorship disputes in classical literature but also demonstrates,from the perspective of structural complexity,the profound depth and unique charm of Chinese literary expression,highlighting the richness of Chinese language and culture.Moreover,it emphasizes the potential of structural complexity analysis as a versatile tool for textual analysis and style attribution.展开更多
Forest structural complexity can mediate the light and water distribution within forest canopies,and has a direct impact on forest biodiversity and carbon storage capability.It is believed that increases in forest str...Forest structural complexity can mediate the light and water distribution within forest canopies,and has a direct impact on forest biodiversity and carbon storage capability.It is believed that increases in forest structural complexity can enhance tree species diversity and forest productivity,but inconsistent relationships among them have been reported.Here,we quantified forest structural complexity in three aspects(i.e.,horizontal,vertical,and internal structural complexity)from unmanned aerial vehicle light detection and ranging data,and investigated their correlations with tree species diversity and forest productivity by incorporating field measurements in three forest biomes with large latitude gradients in China.Our results show that internal structural complexity had a stronger correlation(correlation coefficient=0.85)with tree species richness than horizontal structural complexity(correlation coefficient=-0.16)and vertical structural complexity(correlation coefficient=0.61),and it was the only forest structural complexity attribute having significant correlations with both tree species richness and tree species evenness.A strong scale effect was observed in the correlations among forest structural complexity,tree species diversity,and forest productivity.Moreover,forest internal structural complexity had a tight positive coordinated contribution with tree species diversity to forest productivity through structure equation model analysis,while horizontal and vertical structural complexity attributes have insignificant or weaker coordinated effects than internal structural complexity,which indicated that the neglect of forest internal structural complexity might partially lead to the current inconsistent observations among forest structural complexity,tree species diversity,and forest productivity.The results of this study can provide a new angle to understand the observed inconsistent correlations among forest structural complexity,tree species diversity,and forest productivity.展开更多
Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structura...Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structural components drive arthropod abundance and biomass remains poorly understood in temperate forests.This study examined how local and landscape-scale forest characteristics influence arthropod communities across vertical strata(forest floor(FF),herb layer(HL),and shrub layer(SL))in 19 temperate deciduous forests in Belgium,dominated by pedunculate oak,European beech,or Canadian poplar.At the local scale,we assessed dominant tree species identity,overall forest structural complexity,and its components(vertical and horizontal structure,woody layer,herbal layer,and deadwood).At the landscape scale,we evaluated forest area,edge length,forest cover,and vegetation greenness(normalized difference vegetation index(NDVI)).Contrary to expectation,arthropod biomass and abundance did not consistently increase with higher structural complexity.Instead,woody layer complexity,dominant tree species,and NDVI emerged as key drivers,with effects varying by context and stratum.Arthropod abundance and biomass were the highest in oak-and poplar-dominated forests and the lowest in beech forests,likely due to differences in litter quality,microhabitat availability,and understory development.Woody layer complexity positively influenced forest floor arthropods in poplar forests but had a negative effect in oak forests.At the landscape scale,NDVI unexpectedly showed negative relationships with arthropod abundance across strata and with arthropod biomass in the herb layer,likely reflecting dense canopy suppression of understory productivity.Arthropod biomass on the forest floor increased with forest cover,while abundance in the shrub layer decreased with forest cover but increased with forest area.These findings highlight the complex interplay between forest structural attributes,dominant tree species,and landscape factors in shaping arthropod communities.By identifying the key drivers of arthropod abundance and biomass,this study contributes to a better understanding of biodiversity patterns in temperate forests and their ecological dynamics.展开更多
To clarify the main enrichment-controlling factors and accumulation mechanisms of shale gas in the Permian Dalong Formation within the Western Hubei-Eastern Chongqing complex structural zone,this study systematically ...To clarify the main enrichment-controlling factors and accumulation mechanisms of shale gas in the Permian Dalong Formation within the Western Hubei-Eastern Chongqing complex structural zone,this study systematically reveals the enrichment patterns and accumulation model through analysis of typical drilling data,geochemical testing,scanning electron microscopy(SEM),methane isothermal adsorption experiments,numerical simulations,and research on tectonic evolution and preservation condition.The results are obtained in two aspects.First,the enrichment of shale gas in the Dalong Formation is synergistically controlled by four factors,i.e.rift troughs controlling shale development,provenance controlling reservoir heterogeneity,temperature and pressure controlling gas occurrence,and structure controlling differential enrichment.The geometry and scale of rift troughs(Chengkou-Western Hubei,and Kaijiang-Liangping)determine the development of organic-rich shale(average TOC>6%,thickness of 15-50 m).Multi-source materials lead to strong heterogeneity of the reservoir,with endogenous minerals as the main component(accounting for 74.31%),and the pores mainly organic matter pores(micropores and mesopores accounting for 93.4%).The formation temperature and pressure control the occurrence state of shale gas,with adsorbed gas(higher than 50%)dominantly in 500-2750 m depth,while free gas(higher than 50%)prevailing at depth deeper than 2750 m depth.The uplift,erosion,and fault systems associated with the Yanshanian tectonic activity result in differential enrichment of shale gas,with three structural styles—broad gentle anticlines,residual synclines,and low gentle slopes—exhibiting relatively high shale gas enrichment.Second,the self-sealing mechanism of medium-shallow shale gas in the Western Hubei-Eastern Chongqing complex structural zone is revealed.Specifically,the Dalong Formation shale aquifer forms a lateral seal for shale gas in the downdip direction via water films and capillary forces,and it combines with the overlying Daye Formation limestone and underlying Xiayao Formation tight layers to establish a synclinal/monoclinal self-sealing accumulation model.The geological insights,such as“four-factor synergistic control”and self-sealing accumulation model,provide a dynamic coupling evaluation framework for shale gas in complex structural zones,promoting the transition of shale gas exploration and evaluation from static descriptions to integrated reservoir-tectonic-fluid analysis.展开更多
The preservation of a historical building, whatever its architectural and/or artistic value, is more successful when undertaken with a deep understanding of the building＇s history, development, materials and construc...The preservation of a historical building, whatever its architectural and/or artistic value, is more successful when undertaken with a deep understanding of the building＇s history, development, materials and construction techniques. The preliminary phase of any restoration intervention must start with data acquisition regarding the characteristics and conditions of the building, including a survey of significant alterations. In a great number of cases, restorations are not respectful of the building＇s static efficiency, so its static requirement is weakened. In fact, a very high percentage of instances in which a restoration effort results in building damage is attributable to such modification＇s indifference to the structural balance of a structure, as consolidated over time. This study focuses on the restoration intervention on two trilobate pillars that separate the central space from the presbytery in the Cathedral of Matera, located in southern Italy. Through the use of sonic tests - carried out despite the complexity of the shape of the building and constructive elements that characterize these pillars -- it was possible to show the effectiveness of the implemented intervention, highlighting critical points and weaknesses. The research aims to show how -- despite the complexity of some structural elements of a building -- in-depth knowledge of a structure＇s structure and history is essential to for the success of restoration interventions, which are respectful of a building＇s type and material peculiarities.展开更多
To provide system designer a valid measure to evaluate the structure complexityof class diagrams objectively, this letter first proposes a method to transform a class diagramsinto a weighted class dependence graph, th...To provide system designer a valid measure to evaluate the structure complexityof class diagrams objectively, this letter first proposes a method to transform a class diagramsinto a weighted class dependence graph, then presents a structure complexity measure for classdiagrams based on entropy distance.展开更多
The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-c...The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers.The disordered vip molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin.The vip inside the cavity is disordered over two sites and exhibits mobility.Moreover,2D NMR spectroscopy and theoretical study show the same inclusion behavior.In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid,the host-vip stoichiometries are different,i.e.,2：1 for m-nitrophenoxyacetic acid and 1：1 for p-nitrophenoxyacetic acid,while the inclusion orientation and the packing pattern of the host are similar in both complexes.展开更多
Marine shale gas in the southern Sichuan Basin is the most successful area of shale gas exploration and development in China.In order to open up new shale gas fields and search for new shale gas reserves and productio...Marine shale gas in the southern Sichuan Basin is the most successful area of shale gas exploration and development in China.In order to open up new shale gas fields and search for new shale gas reserves and production replacement blocks,it is necessary to continuously establish and complete the standards on shale gas reservoir evaluation and area selection under different structural settings.The early exploration practice shows that shale in the mountainous complex structural area along the southwestern margin of the Sichuan Basin varies greatly in the gas bearing property,so systematical analysis and study on the shale gas enrichment mechanisms in this area is of great significance to searching for new shale gas exploration areas.Based on drilling data of 5 wells in the mountainous complex structural area along the southwestern margin of the Sichuan Basin,the main factors controlling the shale gas bearing property and the shale gas enrichment model were discussed based on the systematical experiments and analysis of the outcrops,cores and cuttings of Longmaxi Formation shale from the aspects of organic geochemistry,physical property,gas content,hydrocarbon generation history and pore evolution history,so as to lay a solid geological basis for the birth of a new shale gas area.And the following research results were obtained.First,the shale of the first submember of first Member of Longmaxi Formation(S1l11)in the mountainous complex structural area along the southwestern margin of the Sichuan Basin has an average TOC of 3.02%–4.97%and Ro of 2.38%–3.37%,and the average total gas content in local enrichment zones is up to 4.62 m^(3)/t,so it is classified as quality shale.Second,the detailed studies on hydrocarbon generation history indicate that the shale has the characteristics of“low thermal evolution rate and low maturity”.It is characterized by late hydrocarbon generation,low thermal evolution rate,low current maturity and short late diffusion time,which are favorable for shale gas enrichment.Third,the pore evolution history reveals that shale pore evolution can be divided into six stages,i.e.,sharp pore reduction,pore reduction,organic pore formation,pore preservation,organic pore dissipation and karstification,and organic pore and TOC are the most direct control factors of shale gas content.Fourth,favorable shelf facies belt is conducive to the formation of large-scale reservoir space and effective pores,and diversities of preservation conditions under different structural styles and at different structural positions control different pore evolution stages.The shale gas in the mountainous complex structural area is characterized by horizontal zoning and differential enrichment.“Low thermal evolution rate and low maturity”and“slow structural uplifting”are beneficial to the long-term enrichment and preservation of shale gas.In conclusion,the mountainous complex structural area along the southwestern margin of the Sichuan Basin has a shale gas enrichment model of“sedimentation controlling source rocks,diagenesis controlling reservoirs and structure controlling preservation”.This research result provides idea and reference for searching for new shale gas areas and fields.展开更多
The precise and effective measure results of Web applications not only facilitate good comprehension of them, but also benefit to the macro-management of software activities, such as testing, reverse engineering, reus...The precise and effective measure results of Web applications not only facilitate good comprehension of them, but also benefit to the macro-management of software activities, such as testing, reverse engineering, reuse, etc. The paper exploits some researches on measuring the structure complexity of Web application. Through a deep analysis of the configuration and objects＇ interactions of Web system, two conclusions have been drawn：① A generic Web application consists of static web page, dynamic page, component and database object; ② The main interactions have only three styles, that is static link, dynamic link and call/return relation. Based on analysis and modeling of the content of a Web page （static or dynamic）, complexity measure methods of both control logic of script and nesting of HTML code are further discussed. In addition, two methods for measuring the complexity of inte〉page navigation are also addressed by modeling the inte〉page navigation behaviors of Web application via WNG graph.展开更多
A new cyano-bridged Gadolinium^(Ⅲ)-Iron^(Ⅲ)complex{[Gd(DMF)_(3)(DMSO)(H_(2)O)_(3)]2H_(2)0(DMF=N,N·-dimethylformamide;DMSO=dimethylsulfoxidel}was synthesized by the grinding reaction method,.It crysta-]llizes in...A new cyano-bridged Gadolinium^(Ⅲ)-Iron^(Ⅲ)complex{[Gd(DMF)_(3)(DMSO)(H_(2)O)_(3)]2H_(2)0(DMF=N,N·-dimethylformamide;DMSO=dimethylsulfoxidel}was synthesized by the grinding reaction method,.It crysta-]llizes in the triclinic.,space group P1 with ceIl parameters:a=O.90363(2)nm,b=1.25078(3)nm,c=1.41303(1)nm,穋m^(-3),Z=2,Mr=756.72,F(000)=760,Ⅲ)and the approxi-mately oriented octahedrally sixfold-coordinated Fe(Ⅲ)are linked by a cyano-bridge group to construct a dinuclear compound.The{[Gd(DMF)_(3)(DMSO)(H_(2)O)_(3)](Ⅲ)-Fe(Ⅲ)interaction is antiferromagnetic.CCDC:223430.展开更多
Today＇s emergence of nano-micro hybrid structures with almost biological complexity is of fundamental interest. Our ability to adapt intelligently to the challenges has ramifications all the way from fundamentally ch...Today＇s emergence of nano-micro hybrid structures with almost biological complexity is of fundamental interest. Our ability to adapt intelligently to the challenges has ramifications all the way from fundamentally changing research itself, over applications critical to future survival, to posing globally existential dangers. Touching on specific issues such as how complexity relates to the catalytic prowess of multi-metal compounds, we discuss the increasingly urgent issues in nanotechnology also very generally and guided by the motto ＇Bio Is Nature＇s Nanotech＇. Technology belongs to macro-evolution; for example integration with artificial intelligence （AI） is inevitable. Darwinian adaptation manifests as integration of complexity, and awareness of this helps in developing adaptable research methods that can find use across a wide range of research. The second half of this work reviews a diverse range of projects which all benefited from ＇playful＇ programming aimed at dealing with complexity. The main purpose of reviewing them is to show how such projects benefit from and fit in with the general, philosophical approach, proving the relevance of the ＇big picture＇ where it is usually disregarded.展开更多
Compared with other migration methods, reverse-time migration is based on a precise wave equation, not an approximation, and performs extrapolation in the depth domain rather than the time domain. It is highly accurat...Compared with other migration methods, reverse-time migration is based on a precise wave equation, not an approximation, and performs extrapolation in the depth domain rather than the time domain. It is highly accurate and not affected by strong subsurface structure complexity and horizontal velocity variations. The difference method based on triangular grids maintains the simplicity of the difference method and the precision of the finite element method. It can be used directly for forward modeling on models with complex top surfaces and migration without statics preprocessing. We apply a finite difference method based on triangular grids for post-stack reverse-time migration for the first time. Tests on model data verify that the combination of the two methods can achieve near-perfect results in application.展开更多
Multiple sets of marine shale sequences occur in western Hubei Province and its adjacent areas within the Middle-Upper Yangtze region,offering substantial resource potential.However,their shale gas preservation condit...Multiple sets of marine shale sequences occur in western Hubei Province and its adjacent areas within the Middle-Upper Yangtze region,offering substantial resource potential.However,their shale gas preservation conditions differ significantly due to the heterogeneous porosity and fracture system resulting from multistage tectonic reworking.This necessitates developing region-specific evaluation systems and exploitation techniques.Drawing on previous application cases and guided by the research paradigm of geology-engineering integration,this study presents key technologies potentially applicable to shales in western Hubei Province,spanning from reservoir and sweet spot evaluation to fractu ring scheme design and fracturing perfo rmance monitoring.Several insights are gained accordingly.In terms of pore evaluation,the pore heterogeneity caused by compaction and rebound can be quantified using ideal shape coefficients and fractal dimensions,both of which are influenced by structural deformations,thereby guiding reservoir classification.For seismic data interpretation,pre-stack elastic inversion and azimuthal anisotropy inversion can be employed as core techniques,overcoming the limitation of individual post-stack attributes in typically detecting only major faults.Furthermore,the inversion boundaries are constrained using log-seismic joint quality control and geomechanical simulation,contributing to enhanced reliability of sweet spot evaluation and efficient exploration in areas with complex structures.For fracturing scheme design,scientifically formulated well shut-in strategies,tailored to regional geological characteristics,are essential to activate the fracture-matrix imbibition effect.Parameters with vastly different scales used in the design,such as meter-scale fracture halflength and millidarcy-scale fracture conductivity,can be co-optimized using artificial intelligence(AI)algorithms such as the genetic algorithm(GA)and the simultaneous perturbation stochastic approximation(SPSA)algorithm.Dynamic monitoring of fracturing performance can be achieved using trace chemical tracer technology,thereby reducing target ambiguity caused by structural complexity.Research on shale gas in the structurally complex areas of western Hubei faces multiple challenges,spanning from basic geological understanding to development engineering.These challenges create an urgent need for deep interdisciplinary collaboration.Therefore,this study highlights research into geology-engineering integration,aiming to enhance the efficiency of shale gas exploration and development in western Hubei.展开更多
Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.D...Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.Direct manufacturing often leads to high internal surface roughness,which traditional finishing and measuring methods cannot adequately address due to the decreasing size and increasing complexity of internal structures.This is especially true for components like pipes with large aspect ratios,extremely small deep holes,multi-stage bends,cross pipes,and array holes.To meet the high-performance manufacturing demands of these parts,advanced internal surface finishing and roughness measurement technologies have gained significant attention.This review focuses on the challenges and solutions related to internal surface parts with various apertures and complex structures.Internal surface finishing methods are categorized into mechanical finishing,fluid-based finishing,and energy-field-based finishing based on their characteristics.Roughness measurement technologies are divided into tool-probing and non-probing methods.The principles,required equipment,and key parameters of each finishing and measurement approach are discussed in detail.Additionally,the advantages and limitations of these methods are summarized,and future trends are forecasted.This paper serves as a comprehensive guide for researchers and engineers aiming to enhance the internal surface quality of complex structure parts.展开更多
The multifractal characteristics of organic-rich shale developed along the margins of basins are essential for understanding reservoir heterogeneity,gas storage mechanisms,and the identification of favorable explorati...The multifractal characteristics of organic-rich shale developed along the margins of basins are essential for understanding reservoir heterogeneity,gas storage mechanisms,and the identification of favorable exploration targets.This study systematically investigates the pore structure of marine shale in the Zhaotong area of the National Shale Gas Exploration Demonstration Area in China by integrating analytical methods such as X-ray diffraction,low-pressure N_(2) adsorption,and field emission scanning electron microscopy with the Frenkel-HalseyHill fractal model.The results reveal that:(1)four distinct shale lithofacies(SL)types were identified-argillaceous/siliceous mixed SL(Type Ⅰ:M-2),carbonate/siliceous mixed SL(Type Ⅱ:M and M-1),argillaceous-rich siliceous SL(Type Ⅲ:S-3),and carbonate-rich and argillaceous/carbonate siliceous SL(Type Ⅳ:S-1 and S-2);(2)Types Ⅱ and Ⅳ generally exhibit higher fractal dimensions(D_(1),D_(2),and D_(3))than Types Ⅰ and Ⅲ,indicating the former’s more complex pore architectures,rougher pore surfaces,and greater potential for gas adsorption;(3)for Types Ⅰ and Ⅲ,fractal dimensions exhibit positive correlations with organic matter content,pore structural parameters,and gas content,suggesting their effectiveness as indicators of reservoir quality.In contrast,in Types Ⅱ and Ⅳ,the D_(2) dimension is positively correlated with gas content,implying that mesopores play a significant role in gas occurrence,even in tectonically modified settings.These results highlight the utility of fractal analysis as a robust method for evaluating reservoirs in structurally complex geological environments.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275179,11875042,and 12150410309)the Natural Science Foundation of Shanghai(Grant No.21ZR1443900).
文摘The suprachiasmatic nucleus in the hypothalamus is the master circadian clock in mammals,coordinating physiological processes with the 24-hour day–night cycle.Comprising various cell types,the suprachiasmatic nucleus(SCN)integrates environmental signals to maintain complex and robust circadian rhythms.Understanding the complexity and synchrony within SCN neurons is essential for effective circadian clock function.Synchrony involves coordinated neuronal firing for robust rhythms,while complexity reflects diverse activity patterns and interactions,indicating adaptability.Interestingly,the SCN retains circadian rhythms in vitro,demonstrating intrinsic rhythmicity.This study introduces the multiscale structural complexity method to analyze changes in SCN neuronal activity and complexity at macro and micro levels,based on Bagrov et al.’s approach.By examining structural complexity and local complexities across scales,we aim to understand how tetrodotoxin,a neurotoxin that inhibits action potentials,affects SCN neurons.Our method captures critical scales in neuronal interactions that traditional methods may overlook.Validation with the Goodwin model confirms the reliability of our observations.By integrating experimental data with theoretical models,this study provides new insights into the effects of tetrodotoxin(TTX)on neuronal complexities,contributing to the understanding of circadian rhythms.
文摘Aim To present a quantitative method for structural complexity analysis and evaluation of information systems. Methods Based on Petri net modeling and analysis techniques and with the aid of mathematical tools in general net theory(GNT), a quantitative method for structure description and analysis of information systems was introduced. Results The structural complexity index and two related factors, i.e. element complexity factor and connection complexity factor were defined, and the relations between them and the parameters of the Petri net based model of the system were derived. Application example was presented. Conclusion The proposed method provides a theoretical basis for quantitative analysis and evaluation of the structural complexity and can be applied in the general planning and design processes of the information systems.
基金the Advisory Group on Inter-national Agricultural Research(BEAF)at the German Agency for International Cooperation(GIZ)within the German Ministry for Economic Cooperation(BMZ)for funding this research(project number 08.7860.3-001.00“Making the Mekong Con-nected”-MMC).
文摘The horizontal distribution of stems, stand density and the differentiation of tree dimensions are among the most important aspects of stand structure. An increasing complexity of stand structure is often linked to a higher number of species and to greater ecological stability. For quantification, the Structural Complexity Index (SCI) describes structural complexity by means of an area ratio of the surface that is generated by connecting the tree tops of neighbouring trees to form triangles to the surface that is covered by all triangles if projected on a flat plane. Here, we propose two ecologically relevant modifications of the SCI: The degree of mingling of tree attributes, quantified by a vector ruggedness measure, and a stem density term. We investigate how these two modifications influence index values. Data come from forest inventory field plots sampled along a disturbance gradient from heavily disturbed shrub land, through secondary regrowth to mature montane rainforest stands in Mengsong, Xishuangbanna,Yunnan,China. An application is described linking structural complexity, as described by the SCI and its modified versions, to changes in species composition of insect communities. The results of this study show that the Enhanced Structural Complexity Index (ESCI) can serve as a valuable tool for forest managers and ecologists for describing the structural complexity of forest stands and is particularly valuable for natural forests with a high degree of structural complexity.
文摘Beethoven is a famous German pianist, composer, and conductor, and he set the culmination of Western classical, created a romantic music camp precedent. The size of his music in general is very ambitious, mostly concertos, symphonies, operas and other large works, technical approach and structure used is quite complex, people are left with a deep impression. But it works, while small piano pieces, also has music research value, ＂dedicated to Alice＂ is one of the few Beethoven piano pieces. This paper focuses on creative background ＂dedicated to Alice,＂ this elaborate piano works by the complexity of the analysis of the structure of this work is that it reflects the author＇ s ideological soul to explore their musical value.
基金supported by the National Natural Science Foundation of China(Grant No.42276182)the Major Talent Project of Guangxi Zhuang Autonomous Region(Grant No.GXR-2BGQ2525027)+1 种基金the Natural Science and Technology Innovation Development Doubling Program of Guangxi University(Grant No.2023BZRC019)the Guangxi Natural Science Foundation of China(Grant No.2022GXNSFAA035548)。
文摘Structural complexity is a critical factor in maintaining the key ecosystem services of coral reefs,such as fisheries,biodiversity,coastal protection,and ecotourism.However,the resilience of coral reefs to climate change and anthropogenic disturbances remains poorly understood owing to a lack of longterm data.This study used data from field surveys at Weizhou Island in the northern South China Sea,conducted from 2019 to 2024,to record the response trajectories of the coral community and structural complexity,and to estimate the key drivers in a relatively high-latitude coral reef.Following a bleaching event in 2020 and disturbance by two cyclones in 2023,live coral cover(LCC) initially declined but later recovered,suggesting a gain in thermal tolerance.Corals in the marine protected area(MPA) were less impacted than those in the non-protected area.However,the structural complexity decreased continuously,from 1.200 to 1.076,signifying simplification in coral morphological composition.Despite the decline in structural complexity,a significant positive correlation with fish density was observed in the MPA(R^(2)=0.91,p<0.05).Bayesian and generalized linear models identified thermal stress,cyclones,and anthropogenic activity as the primary drivers of the loss of structural complexity.These results,along with the divergent trajectories of LCC and structural complexity,highlight the limited resilience of a relatively high-latitude coral reef to climate change.The findings of this study demonstrate how an MPA can play a crucial role in enhancing ecosystem resilience by reducing local stressors and allowing marine life to recover,enabling the ecosystem to withstand a wider-reaching threat such as climate change.We recommend incorporating structural complexity into long-term monitoring and management networks for coral reef ecosystems facing climate change.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12275179,11875042,and12150410309)the Natural Science Foundation of Shanghai(Grant No.21ZR1443900)。
文摘Text,as a fundamental carrier of human language and culture,exhibits high structural and semantic complexity.Its systematic analysis is essential for understanding linguistic patterns and cultural transmission.A Dream of Red Mansions and All Men Are Brothers,two masterpieces of Chinese classical literature,have long been central to debates regarding the authorship of their later chapters.Previous studies,often based on word-frequency statistics,function word distributions,entropy measures,and complex network analyses,have provided valuable insights into stylistic differences;however,they remain limited in capturing cross-scale structural features.To address this gap,we apply a multi-scale structural complexity approach based on character-frequency time series to analyze the structural evolution of both novels under various segmentation strategies.Our results reveal significant differences in peak complexity positions,overall complexity levels,and intra-textual variations between the two works,which are closely linked to changes in authorship and stylistic patterns.This study not only provides new quantitative evidence for resolving authorship disputes in classical literature but also demonstrates,from the perspective of structural complexity,the profound depth and unique charm of Chinese literary expression,highlighting the richness of Chinese language and culture.Moreover,it emphasizes the potential of structural complexity analysis as a versatile tool for textual analysis and style attribution.
基金supported by the Frontier Science Key Programs of the Chinese Academy of Sciences(QYZDY-SSW-SMC011)the National Natural Science Foundation of China(41871332,31971575,41901358).
文摘Forest structural complexity can mediate the light and water distribution within forest canopies,and has a direct impact on forest biodiversity and carbon storage capability.It is believed that increases in forest structural complexity can enhance tree species diversity and forest productivity,but inconsistent relationships among them have been reported.Here,we quantified forest structural complexity in three aspects(i.e.,horizontal,vertical,and internal structural complexity)from unmanned aerial vehicle light detection and ranging data,and investigated their correlations with tree species diversity and forest productivity by incorporating field measurements in three forest biomes with large latitude gradients in China.Our results show that internal structural complexity had a stronger correlation(correlation coefficient=0.85)with tree species richness than horizontal structural complexity(correlation coefficient=-0.16)and vertical structural complexity(correlation coefficient=0.61),and it was the only forest structural complexity attribute having significant correlations with both tree species richness and tree species evenness.A strong scale effect was observed in the correlations among forest structural complexity,tree species diversity,and forest productivity.Moreover,forest internal structural complexity had a tight positive coordinated contribution with tree species diversity to forest productivity through structure equation model analysis,while horizontal and vertical structural complexity attributes have insignificant or weaker coordinated effects than internal structural complexity,which indicated that the neglect of forest internal structural complexity might partially lead to the current inconsistent observations among forest structural complexity,tree species diversity,and forest productivity.The results of this study can provide a new angle to understand the observed inconsistent correlations among forest structural complexity,tree species diversity,and forest productivity.
基金supported by the UGent GOA project“Forest biodiversity and multifunctionality drive chronic stress-mediated dynamics in pathogen reservoirs(FORESTER)”(No.BOF20/GOA/009).
文摘Forest structural complexity influences arthropod communities by shaping habitat availability,microclimatic conditions,and resource distribution.However,the extent to which structural complexity and specific structural components drive arthropod abundance and biomass remains poorly understood in temperate forests.This study examined how local and landscape-scale forest characteristics influence arthropod communities across vertical strata(forest floor(FF),herb layer(HL),and shrub layer(SL))in 19 temperate deciduous forests in Belgium,dominated by pedunculate oak,European beech,or Canadian poplar.At the local scale,we assessed dominant tree species identity,overall forest structural complexity,and its components(vertical and horizontal structure,woody layer,herbal layer,and deadwood).At the landscape scale,we evaluated forest area,edge length,forest cover,and vegetation greenness(normalized difference vegetation index(NDVI)).Contrary to expectation,arthropod biomass and abundance did not consistently increase with higher structural complexity.Instead,woody layer complexity,dominant tree species,and NDVI emerged as key drivers,with effects varying by context and stratum.Arthropod abundance and biomass were the highest in oak-and poplar-dominated forests and the lowest in beech forests,likely due to differences in litter quality,microhabitat availability,and understory development.Woody layer complexity positively influenced forest floor arthropods in poplar forests but had a negative effect in oak forests.At the landscape scale,NDVI unexpectedly showed negative relationships with arthropod abundance across strata and with arthropod biomass in the herb layer,likely reflecting dense canopy suppression of understory productivity.Arthropod biomass on the forest floor increased with forest cover,while abundance in the shrub layer decreased with forest cover but increased with forest area.These findings highlight the complex interplay between forest structural attributes,dominant tree species,and landscape factors in shaping arthropod communities.By identifying the key drivers of arthropod abundance and biomass,this study contributes to a better understanding of biodiversity patterns in temperate forests and their ecological dynamics.
基金Supported by the National Natural Science Foundation of China(42472210)Project of the China Geological Survey(DD20221653,DD20230043).
文摘To clarify the main enrichment-controlling factors and accumulation mechanisms of shale gas in the Permian Dalong Formation within the Western Hubei-Eastern Chongqing complex structural zone,this study systematically reveals the enrichment patterns and accumulation model through analysis of typical drilling data,geochemical testing,scanning electron microscopy(SEM),methane isothermal adsorption experiments,numerical simulations,and research on tectonic evolution and preservation condition.The results are obtained in two aspects.First,the enrichment of shale gas in the Dalong Formation is synergistically controlled by four factors,i.e.rift troughs controlling shale development,provenance controlling reservoir heterogeneity,temperature and pressure controlling gas occurrence,and structure controlling differential enrichment.The geometry and scale of rift troughs(Chengkou-Western Hubei,and Kaijiang-Liangping)determine the development of organic-rich shale(average TOC>6%,thickness of 15-50 m).Multi-source materials lead to strong heterogeneity of the reservoir,with endogenous minerals as the main component(accounting for 74.31%),and the pores mainly organic matter pores(micropores and mesopores accounting for 93.4%).The formation temperature and pressure control the occurrence state of shale gas,with adsorbed gas(higher than 50%)dominantly in 500-2750 m depth,while free gas(higher than 50%)prevailing at depth deeper than 2750 m depth.The uplift,erosion,and fault systems associated with the Yanshanian tectonic activity result in differential enrichment of shale gas,with three structural styles—broad gentle anticlines,residual synclines,and low gentle slopes—exhibiting relatively high shale gas enrichment.Second,the self-sealing mechanism of medium-shallow shale gas in the Western Hubei-Eastern Chongqing complex structural zone is revealed.Specifically,the Dalong Formation shale aquifer forms a lateral seal for shale gas in the downdip direction via water films and capillary forces,and it combines with the overlying Daye Formation limestone and underlying Xiayao Formation tight layers to establish a synclinal/monoclinal self-sealing accumulation model.The geological insights,such as“four-factor synergistic control”and self-sealing accumulation model,provide a dynamic coupling evaluation framework for shale gas in complex structural zones,promoting the transition of shale gas exploration and evaluation from static descriptions to integrated reservoir-tectonic-fluid analysis.
文摘The preservation of a historical building, whatever its architectural and/or artistic value, is more successful when undertaken with a deep understanding of the building＇s history, development, materials and construction techniques. The preliminary phase of any restoration intervention must start with data acquisition regarding the characteristics and conditions of the building, including a survey of significant alterations. In a great number of cases, restorations are not respectful of the building＇s static efficiency, so its static requirement is weakened. In fact, a very high percentage of instances in which a restoration effort results in building damage is attributable to such modification＇s indifference to the structural balance of a structure, as consolidated over time. This study focuses on the restoration intervention on two trilobate pillars that separate the central space from the presbytery in the Cathedral of Matera, located in southern Italy. Through the use of sonic tests - carried out despite the complexity of the shape of the building and constructive elements that characterize these pillars -- it was possible to show the effectiveness of the implemented intervention, highlighting critical points and weaknesses. The research aims to show how -- despite the complexity of some structural elements of a building -- in-depth knowledge of a structure＇s structure and history is essential to for the success of restoration interventions, which are respectful of a building＇s type and material peculiarities.
基金Supported in part by the National Natural Science Foundation of China(60073012),National Grand Fundamental Research 973 Program of China(G1999032701),Natural Research Foundation for the Doctoral Program of Higher Education of China,Natural Science Founda
文摘To provide system designer a valid measure to evaluate the structure complexityof class diagrams objectively, this letter first proposes a method to transform a class diagramsinto a weighted class dependence graph, then presents a structure complexity measure for classdiagrams based on entropy distance.
文摘The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction,2D NMR spectroscopy and semi-empirical methods AMI.The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers.The disordered vip molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin.The vip inside the cavity is disordered over two sites and exhibits mobility.Moreover,2D NMR spectroscopy and theoretical study show the same inclusion behavior.In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid,the host-vip stoichiometries are different,i.e.,2：1 for m-nitrophenoxyacetic acid and 1：1 for p-nitrophenoxyacetic acid,while the inclusion orientation and the packing pattern of the host are similar in both complexes.
基金supported by the National Major Science and Technology Project“Test and application of reconnaissance and evaluation technologies for shale gas”(No.:2016ZX05034004)the Project of China Geological Survey“Basic geologic survey of Lower Paleozoic marine shale gas in Sichuan Basin”(No.:DD20160176)+1 种基金“Survey on strategic zone of shale gas in Longmaxi Formation,Sichuan Basin”(No.:DD20160193)“Survey on shale gas enrichment conditions in Sichuan Basin”(No.:12120114071401).
文摘Marine shale gas in the southern Sichuan Basin is the most successful area of shale gas exploration and development in China.In order to open up new shale gas fields and search for new shale gas reserves and production replacement blocks,it is necessary to continuously establish and complete the standards on shale gas reservoir evaluation and area selection under different structural settings.The early exploration practice shows that shale in the mountainous complex structural area along the southwestern margin of the Sichuan Basin varies greatly in the gas bearing property,so systematical analysis and study on the shale gas enrichment mechanisms in this area is of great significance to searching for new shale gas exploration areas.Based on drilling data of 5 wells in the mountainous complex structural area along the southwestern margin of the Sichuan Basin,the main factors controlling the shale gas bearing property and the shale gas enrichment model were discussed based on the systematical experiments and analysis of the outcrops,cores and cuttings of Longmaxi Formation shale from the aspects of organic geochemistry,physical property,gas content,hydrocarbon generation history and pore evolution history,so as to lay a solid geological basis for the birth of a new shale gas area.And the following research results were obtained.First,the shale of the first submember of first Member of Longmaxi Formation(S1l11)in the mountainous complex structural area along the southwestern margin of the Sichuan Basin has an average TOC of 3.02%–4.97%and Ro of 2.38%–3.37%,and the average total gas content in local enrichment zones is up to 4.62 m^(3)/t,so it is classified as quality shale.Second,the detailed studies on hydrocarbon generation history indicate that the shale has the characteristics of“low thermal evolution rate and low maturity”.It is characterized by late hydrocarbon generation,low thermal evolution rate,low current maturity and short late diffusion time,which are favorable for shale gas enrichment.Third,the pore evolution history reveals that shale pore evolution can be divided into six stages,i.e.,sharp pore reduction,pore reduction,organic pore formation,pore preservation,organic pore dissipation and karstification,and organic pore and TOC are the most direct control factors of shale gas content.Fourth,favorable shelf facies belt is conducive to the formation of large-scale reservoir space and effective pores,and diversities of preservation conditions under different structural styles and at different structural positions control different pore evolution stages.The shale gas in the mountainous complex structural area is characterized by horizontal zoning and differential enrichment.“Low thermal evolution rate and low maturity”and“slow structural uplifting”are beneficial to the long-term enrichment and preservation of shale gas.In conclusion,the mountainous complex structural area along the southwestern margin of the Sichuan Basin has a shale gas enrichment model of“sedimentation controlling source rocks,diagenesis controlling reservoirs and structure controlling preservation”.This research result provides idea and reference for searching for new shale gas areas and fields.
基金Supported by the Defense Pre-Research Project ofthe 10th Five-Year Plan of China (413150902) ,andthe Defense Pre-Research Project of the Navy Equipment Ministry (10104010201)
文摘The precise and effective measure results of Web applications not only facilitate good comprehension of them, but also benefit to the macro-management of software activities, such as testing, reverse engineering, reuse, etc. The paper exploits some researches on measuring the structure complexity of Web application. Through a deep analysis of the configuration and objects＇ interactions of Web system, two conclusions have been drawn：① A generic Web application consists of static web page, dynamic page, component and database object; ② The main interactions have only three styles, that is static link, dynamic link and call/return relation. Based on analysis and modeling of the content of a Web page （static or dynamic）, complexity measure methods of both control logic of script and nesting of HTML code are further discussed. In addition, two methods for measuring the complexity of inte〉page navigation are also addressed by modeling the inte〉page navigation behaviors of Web application via WNG graph.
文摘A new cyano-bridged Gadolinium^(Ⅲ)-Iron^(Ⅲ)complex{[Gd(DMF)_(3)(DMSO)(H_(2)O)_(3)]2H_(2)0(DMF=N,N·-dimethylformamide;DMSO=dimethylsulfoxidel}was synthesized by the grinding reaction method,.It crysta-]llizes in the triclinic.,space group P1 with ceIl parameters:a=O.90363(2)nm,b=1.25078(3)nm,c=1.41303(1)nm,穋m^(-3),Z=2,Mr=756.72,F(000)=760,Ⅲ)and the approxi-mately oriented octahedrally sixfold-coordinated Fe(Ⅲ)are linked by a cyano-bridge group to construct a dinuclear compound.The{[Gd(DMF)_(3)(DMSO)(H_(2)O)_(3)](Ⅲ)-Fe(Ⅲ)interaction is antiferromagnetic.CCDC:223430.
基金jointly supported by the Natural Science Foundation of Jiangsu Province (No.2012729)the Innovation Fund of Jiangsu Province (No.BY2013072-06)the National Natural Science Foundation of China (No.51171078 and No.11374136)
文摘Today＇s emergence of nano-micro hybrid structures with almost biological complexity is of fundamental interest. Our ability to adapt intelligently to the challenges has ramifications all the way from fundamentally changing research itself, over applications critical to future survival, to posing globally existential dangers. Touching on specific issues such as how complexity relates to the catalytic prowess of multi-metal compounds, we discuss the increasingly urgent issues in nanotechnology also very generally and guided by the motto ＇Bio Is Nature＇s Nanotech＇. Technology belongs to macro-evolution; for example integration with artificial intelligence （AI） is inevitable. Darwinian adaptation manifests as integration of complexity, and awareness of this helps in developing adaptable research methods that can find use across a wide range of research. The second half of this work reviews a diverse range of projects which all benefited from ＇playful＇ programming aimed at dealing with complexity. The main purpose of reviewing them is to show how such projects benefit from and fit in with the general, philosophical approach, proving the relevance of the ＇big picture＇ where it is usually disregarded.
基金sponsored by National Natural Science Foundation(40474041)National Symposium of 863(2006AA06Z206)+1 种基金National Symposium of 973(2007CB209605)CNPC Geophysical Key Laboratory of the China University of Petroleum (East China) Research Department
文摘Compared with other migration methods, reverse-time migration is based on a precise wave equation, not an approximation, and performs extrapolation in the depth domain rather than the time domain. It is highly accurate and not affected by strong subsurface structure complexity and horizontal velocity variations. The difference method based on triangular grids maintains the simplicity of the difference method and the precision of the finite element method. It can be used directly for forward modeling on models with complex top surfaces and migration without statics preprocessing. We apply a finite difference method based on triangular grids for post-stack reverse-time migration for the first time. Tests on model data verify that the combination of the two methods can achieve near-perfect results in application.
基金supported by the Excellence Research Group Program of the Hubei Provincial Natural Science Foundation(originally termed Basic Science Center Program)(JCKXXM202500016)the Key Program of the National Natural Science Foundation of China(42230812)the National Natural Science Foundation of China(42073068)。
文摘Multiple sets of marine shale sequences occur in western Hubei Province and its adjacent areas within the Middle-Upper Yangtze region,offering substantial resource potential.However,their shale gas preservation conditions differ significantly due to the heterogeneous porosity and fracture system resulting from multistage tectonic reworking.This necessitates developing region-specific evaluation systems and exploitation techniques.Drawing on previous application cases and guided by the research paradigm of geology-engineering integration,this study presents key technologies potentially applicable to shales in western Hubei Province,spanning from reservoir and sweet spot evaluation to fractu ring scheme design and fracturing perfo rmance monitoring.Several insights are gained accordingly.In terms of pore evaluation,the pore heterogeneity caused by compaction and rebound can be quantified using ideal shape coefficients and fractal dimensions,both of which are influenced by structural deformations,thereby guiding reservoir classification.For seismic data interpretation,pre-stack elastic inversion and azimuthal anisotropy inversion can be employed as core techniques,overcoming the limitation of individual post-stack attributes in typically detecting only major faults.Furthermore,the inversion boundaries are constrained using log-seismic joint quality control and geomechanical simulation,contributing to enhanced reliability of sweet spot evaluation and efficient exploration in areas with complex structures.For fracturing scheme design,scientifically formulated well shut-in strategies,tailored to regional geological characteristics,are essential to activate the fracture-matrix imbibition effect.Parameters with vastly different scales used in the design,such as meter-scale fracture halflength and millidarcy-scale fracture conductivity,can be co-optimized using artificial intelligence(AI)algorithms such as the genetic algorithm(GA)and the simultaneous perturbation stochastic approximation(SPSA)algorithm.Dynamic monitoring of fracturing performance can be achieved using trace chemical tracer technology,thereby reducing target ambiguity caused by structural complexity.Research on shale gas in the structurally complex areas of western Hubei faces multiple challenges,spanning from basic geological understanding to development engineering.These challenges create an urgent need for deep interdisciplinary collaboration.Therefore,this study highlights research into geology-engineering integration,aiming to enhance the efficiency of shale gas exploration and development in western Hubei.
基金the financial supports from National Key R&D Program of China(No.2022YFB3403301)the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.52311530080)。
文摘Modern industrial equipment is increasingly characterized by miniaturization,integration,and high performance,necessitating the production of complex structural parts with exceptionally high internal surface quality.Direct manufacturing often leads to high internal surface roughness,which traditional finishing and measuring methods cannot adequately address due to the decreasing size and increasing complexity of internal structures.This is especially true for components like pipes with large aspect ratios,extremely small deep holes,multi-stage bends,cross pipes,and array holes.To meet the high-performance manufacturing demands of these parts,advanced internal surface finishing and roughness measurement technologies have gained significant attention.This review focuses on the challenges and solutions related to internal surface parts with various apertures and complex structures.Internal surface finishing methods are categorized into mechanical finishing,fluid-based finishing,and energy-field-based finishing based on their characteristics.Roughness measurement technologies are divided into tool-probing and non-probing methods.The principles,required equipment,and key parameters of each finishing and measurement approach are discussed in detail.Additionally,the advantages and limitations of these methods are summarized,and future trends are forecasted.This paper serves as a comprehensive guide for researchers and engineers aiming to enhance the internal surface quality of complex structure parts.
基金supported by the National Natural Science Foundation of China(Grant No.42272163)the Fund of State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China)(Grant No.SKLDOG2024-ZYTS-01).
文摘The multifractal characteristics of organic-rich shale developed along the margins of basins are essential for understanding reservoir heterogeneity,gas storage mechanisms,and the identification of favorable exploration targets.This study systematically investigates the pore structure of marine shale in the Zhaotong area of the National Shale Gas Exploration Demonstration Area in China by integrating analytical methods such as X-ray diffraction,low-pressure N_(2) adsorption,and field emission scanning electron microscopy with the Frenkel-HalseyHill fractal model.The results reveal that:(1)four distinct shale lithofacies(SL)types were identified-argillaceous/siliceous mixed SL(Type Ⅰ:M-2),carbonate/siliceous mixed SL(Type Ⅱ:M and M-1),argillaceous-rich siliceous SL(Type Ⅲ:S-3),and carbonate-rich and argillaceous/carbonate siliceous SL(Type Ⅳ:S-1 and S-2);(2)Types Ⅱ and Ⅳ generally exhibit higher fractal dimensions(D_(1),D_(2),and D_(3))than Types Ⅰ and Ⅲ,indicating the former’s more complex pore architectures,rougher pore surfaces,and greater potential for gas adsorption;(3)for Types Ⅰ and Ⅲ,fractal dimensions exhibit positive correlations with organic matter content,pore structural parameters,and gas content,suggesting their effectiveness as indicators of reservoir quality.In contrast,in Types Ⅱ and Ⅳ,the D_(2) dimension is positively correlated with gas content,implying that mesopores play a significant role in gas occurrence,even in tectonically modified settings.These results highlight the utility of fractal analysis as a robust method for evaluating reservoirs in structurally complex geological environments.
